Monster In law

My best friend lives with me and my fiancé in our apartment, my fiancés mom lives in the same building but downstairs from us. Tonight while me and my fiancé were out, my best friend was downstairs with my MIL and recorded her talking shit about me without her knowing. She was saying I'm lazy and I don't take care of the house or do anything and how I shouldn't be trying to get pregnant and just going on and on downing me. (We're not even trying to get pregnant - she's the one begging for a grandchild everyday. I quit taking my birth control because I'm having a bad reaction to it which put me in the hospital today and she even talked shit about that) and I've applied in so many places plus I just graduated high school and I'm enrolled in college. I had a good job but due to medical problems I had to quit and I've been home since. We've always had an off relationship because she has a really close relationship with her two sons and neither of them can do anything wrong in her eyes. My fiancé is mad at my best friend for recording it and mad at me for wanting to stick up for myself. Do I have the right to be mad or am I overreacting? I told him stick up for me or I'll do it myself and either we're moving or I'm leaving. I'm tired of not feeling at home in my own home because of her.